Hunting gun with floating bolt provided with a device for locking the bolt head in the bolt breech upon firing

ABSTRACT

The hunting gun has a bolt assembly comprising two parts, namely a locking head and a floating element with a spring interposed between the two parts. The locking head comprises essentially one or more projections adapted to engage corresponding recesses in the cylindrical internal surface of the breech and a surface inclined with respect to the breech axis and adapted to engage a mating surface of the floating element. Upon firing the gun recoils but the floating element, being free in the gun, tends to keep its position and keeps the locking head with its projections in engagement with the grooves in the breech. Thus, there is a delay in the opening of the cartridge chamber, which prevents unlocking of the gun in the charge explosion step, i.e. at the time of greatest gas expansion. When the recoil force has decreased to a predetermined extent the spring pushes back the floating element which slides with its inclined surface on the mating surface of the locking head permitting the latter to lower and disengage its projections from the recesses in the breech so that the locking head can also recoil under the action of the residual force of the spring.

Unite States Benelli [451 Jan.14,1975

[ HUNTING GUN WITH FLOATING BOLT PROVIDED WITH A DEVICE FOR LOCKING THEBOLT HEAD IN THE BOLT BREECH UPON FIRING [75] Inventor: GiovanniBenelli, Urbino, Italy [73] Assignee: Benelli S.p.A. Divisione Armi [22]Filed: July 16, 1973 21 Appl. No.: 379,604

[30] Foreign Application Priority Data [5 7] ABSTRACT The hunting gunhas a bolt assembly comprising two parts, namely a locking head and afloating element with a spring interposed between the two parts. Thelocking head comprises essentially one or more projections adapted toengage corresponding recesses in the cylindrical internal surface of thebreech and a surface inclined with respect to the breech axis andadapted to engage a mating surface of the floating element. Upon firingthe gun recoils but the floating element, being free in the gun, tendsto keep its position and keeps the locking head with its projections inengagement with the grooves in the breech. Thus, there is a delay in theopening of the cartridge chamber, which prevents unlocking of the gun inthe charge explosion step, i.e. at the time of greatest gas expansion.When the recoil force has decreased to a predetermined extent the springpushes back the floating element which slides with its inclined surfaceon the mating surface of the locking head permitting the latter to lowerand disengage its projections from the recesses in the breech so thatthe locking head can also recoil under the action of the residual forceof the spring.

6 Claims, 5 Drawing Figures July 18, 1972 Italy 27099/72 [52] US. Cl.42/16, 89/190 [51] Int. Cl F41c 11/06, F41d 3/06 [58] Field of Search42/16, 17; 89/190, 176, 89/182-183, 194

[56] References Cited UNITED STATES PATENTS 2,424,264 7/1947 Yorks 42/162,570,772 10/1951 Crittendon 89/190 2,887,808 5/1959 Janson et a1. 42/17Primary ExaminerBenjamin A. Borchelt Assistant Examiner--C. T. JordanAttorney, Agent, or Firm-Amster & Rothstein 1 A l u l floo LL/N 51 0 0 oMILLW HUNTING GUN WITH FLOATING BOLT PROVIDED WITH A DEVICE FOR LOCKINGTHE BOLT HEAD IN THEBOLT BREECI-I UPON FIRING This invention relates toa hunting gun, of the kind disclosed in the Italian Patent No. 762319issued to the applicant of this invention.

The hunting gun disclosed in the above Italian patent is provided with abolt assembly consisting in two portions, namely a locking bolt head anda floating element adapted to axially reciprocate with respect to thelocking bolt head and to unlock it during the movement in one of the twodirections, a spring being interposed between said two portions.

Upon firing, the weapon undergoes a recoiling action due to the pressuredeveloped by gases generated upon the explosion of the cartridge chargecaused by the firing pin, however, the floating element being free withrespect to the breech, accomplishes by its inertia an axial movementrelative to the locking bolt head,-

thereby compressing the spring interposed between the floating elementand the bolt head. This prevents the weapon from being unlocked duringthe charge explosion step, i.e. at the time of maximum gas expansionthereby avoiding a premature weapon unlocking. Only when the recoilingaction has been attenuated to a predetermined value, the spring reactingto the compression to which it had been subjected bythe inertialmass ofthe floating element, throws back again the floating element whichcauses the unlocking of the locking bolt head, so that also the latteris recoiled partly under the action of the spring and partly under theaction of the residual gases. This causes in a conventional manner thecartridge ejection, the loading of the weapon and the locking of a freshcartridge in the cartridge chamber.

In the above Italian patent the locking device of the locking bolt headcomprises a push rod, which in the locking position of the locking bolthead is placed between the locking bolt head and a shoulder provided inthe breech, and is adapted to be disengaged from the breech during thereturn stroke of the bolt floating element and to be entrained by thefloating element during its stroke.

This invention aims to make the locking device of the bolt head moresimple and economical.

More particularly the hunting gun according to this invention ischaracterized in that the locking bolt head comprises a first surfaceprovided with one or more projections adapted to engage in correspondingrecesses provided in the cylindrical internal surface of the breech, asecond surface adapted to engage a mating surface of the floatingelement of the bolt and to slide thereon during the initial intertialmovement of the floating element so as to maintain the projections ofthe first surface in the corresponding recesses of the second surface,said two mating surfaces under these conditions being substantiallyparallel to the breech axis, and a third surface, inclined with respectto the breech axis and adapted to engage a mating surface of thefloating element and to slide thereon during the next back movement ofthe floating element so as to permit the projection or projections todisengage from the corrsponding recesses provided in the breech.

The invention will be more apparent from the following description,merely given by way of example of an embodiment of the invention takenin connection with the accompanying drawing, wherein:

FIG. 1 is a fragmentary axial section of a hunting gun according to theinvention, in "the firing step of the weapon;

FIG. 2 is a fragmentary axial section of the gun shown in FIG. 1, in theunlocking step of the weapon;

FIG. 3A is a side elevation view of the locking bolt head of the weaponshown in FIGS. 1 and 2;

FIG. 3B is a top plan view of the locking bolt head shown in FIG. 3A;and

FIG. 4 is a side elevation of the bolt floating element of the weaponshown in FIGS. 1 and 2.

Referring now to FIG. 1, there is shown the locking bolt head 1 which,upon firing, locks the cartridge 2 into the cartridge chamber 17 throughthe engagement of three curved ribs 3 extending from a curved surface 15of the bolt head into corresponding curved grooves (see FIG. 2) providedin the breech 7. This engagement is assured by the engagement of a flat13 (see FIG. 4) provided in the floating element 9 of the bolt, with aflat 16 (see FIG. 3A) of the locking bolt head 1. A spring 10 is placedbetween the locking bolt head 1 and the floating element 9. The lockingbolt head 1 is also provided with two inclined surfaces 8 (see FIGS. 3Aand 38) adapted to cooperate with mating inclined surfaces 12 providedin the floating element 9.

In FIG. 1 the weapon is shown at the time of firing. The hammer 18 hasbeen brought by the actuation of the trigger (not shown) in contact withthe firing pin 19 which by striking the explosive charge of thecartridge 2 causes the explosion of the charge with resulting gasrelease and ejection of the small shot charge 20. The weapon recoils byreaction against the shooter shoulder, however the bolt floating element9, being out of engagement with the remainder of the gun, has thetendency to maintain its own position thereby compressing the spring 10interposed between the floating element and the locking head 1. Duringthis step the flat 16 of the locking head slides with respect 'to theflat 13 of the floating element 9 which keeps the locking head in theposition shown in FIG. 1, with the ribs 3 in engagement within thegrooves 14 in the breech 7. Therefore, in this step the locking head islocked and closes the cartridge chamber 17. Thus, there is a delay inthe cartridge chamber opening which prevents unlocking of the weapon inthe charge explosion step, i.e. at the time of greater gas expansion.Therefore, at the time more dangerous there will never be a prematureopening of the weapon.

As the recoil force is decreased to a predetermined value at which thespring 10 has been calibrated, the latter pushes back the bolt floatingelement 9 by means of the force stored during the compression of thespring 10 and as the inclined surfaces 12 of the floating element 9,during this recoil movement, lie at the inclined surfaces 8 of thelocking head 1, the latter is able to lower itself, due to the mutualsliding movement of the mating surfaces with respect to the breech 7until the ribs 3 are disengaged from the grooves 14 of the breech 7. Atthis time also the locking head 1 can recoil under the action of theresidual force stored by the spring 10 and by means of the residualgases opens the cartridge chamber thereby permitting the cartridge case21 to be ejected. This return step of the bolt floating element 9 andthe locking head 1 is shown in FIG. 2.

During the return stroke the bolt will cause in a conventional mannerthe reloading and locking of the gun I which will be ready for a newshot.

7 shown and described, it should be understood that various changes andmodifications cana be devised without departing from the scope of theinvention. Thus, for example, while in the specific embodiment describedherein the projections of the locking head and the recesses of thebreech intended to receive said projections are in number of three,these projections and recesses can be more or less than three and couldbe reduced to one only,

What I claim is:

1. A hunting gun having a cartridge chamber and a breech extending alongan axis including a cylindrical internal surface, said gun provided witha bolt assembly comprising a locking bolt head and a floating elementadapted for axial movement in back and forth directions with respect tothe locking bolt head and to unlock it during the movement in one of thetwo directions, and a spring interposed between said locking bolt headand said floating element, characterized in that said locking bolt headcomprises a first surface provided with at least one projection adaptedto engage in corresponding recesses provided in the cylindrical internal surface of the breech, a second surface adapted to engage a firstmating surface of the floating element of the bolt assembly and to slidethereon during the initial inertial movement of the floating element soas to maintain said at least one projection of the first surface in thecorresponding recesses of the second surface, said two mating surfacesunder these conditions being substantially parallel to the breech axis,and a third surface, said third surface being inclined with respect tothe breech axis and adapted to engage a second mating surface of thefloating element and to slide thereon dur ing a next back directionmovement of the floating element so as to permit said at least oneprojection to disengage from the corresponding recesses provided in thebreech.

2. A hunting gun according to claim 1, characterized in that said firstsurface of the locking bolt head, said at least one projection thereofand said recesses provided in the cylindrical internal surface ofthebreech are curved.

3. A hunting gun according to claim 1, characterized in that said secondand third surfaces of said locking bolt head and said cooperatingsurfaces of said bolt floating element are flat surfaces.

4. A huntinggun according to claim 3, characterized in that saidinclined surfaces of said locking bolt head and said bolt floatingelement merge in the surfaces of said elements substantially parallel tothe breech axis.

5. A hunting gun according to claim 1, characterized in that said thirdinclined surface of said locking bolt head comprises two distinct areasdisposed at both sides of said first and second surfaces of said lockingbolt head.

6. A hunting gun according to claim 1, characterized in that saidlocking bolt head comprises a short cylindrical section intended toclose the cartride chamber, and a rod-shaped extension carrying saidprojection and said second and third surfaces cooperating with saidfirst and second mating surfaces respectively of said bolt floatingelement, and said floating element is substantially cylinder-shaped,said floating element being provided with a longitudinal slot intendedto receive said rod-shaped extension of said locking bolt head.

1. A hunting gun having a cartridge chamber and a breech extending alongan axis including a cylindrical internal surface, said gun provided witha bolt assembly comprising a locking bolt head and a floating elementadapted for axial movement in back and forth directions with respect tothe locking bolt head and to unlock it during the movement in one of thetwo directions, and a spring interposed between said locking bolt headand said floating element, characterized in that said locking bolt headcomprises a first surface provided with at least one projection adaptedto engage in corresponding recesses provided in the cylindrical internalsurface of the breech, a second surface adapted to engage a first matingsurface of the floating element of the bolt assembly and to slidethereon during the initial inertial movement of the floating element soas to maintain said at least one projection of the first surface in thecorresponding recesses of the second surface, said two mating surfacesunder these conditions being substantially parallel to the breech axis,and a third surface, said third surface being inclined with respect tothe breech axis and adapted to engage a second mating surface of thefloating element and to slide thereon during a next back directionmovement of the floating element so as to permit said at least oneprojection to disengage from the corresponding recesses provided in thebreech.
 2. A hunting gun according to claim 1, characterized in thatsaid first surface of the locking bolt head, said at least oneprojection thereof and said recesses provided in the cylindricalinternal surface of the breech are curved.
 3. A hunting gun according toclaim 1, characterized in that said second and third surfaces of saidlocking bolt head and said cooperating surfaces of said bolt floatingelement are flat surfaces.
 4. A hunting gun according to claim 3,characterized in that said inclined surfaces of said locking bolt headand said bolt floating element merge in the surfaces of said elementssubstantially parallel to the breech axis.
 5. A hunting gun according toclaim 1, characterized in that said third inclined surface of saidlocking bolt head comprises two distinct areas disposed at both sides ofsaid first and second surfaces of said locking bolt head.
 6. A huntinggun according to claim 1, characterized in that said locking bolt headcomprises a short cylindrical section intended to close thE cartridechamber, and a rod-shaped extension carrying said projection and saidsecond and third surfaces cooperating with said first and second matingsurfaces respectively of said bolt floating element, and said floatingelement is substantially cylinder-shaped, said floating element beingprovided with a longitudinal slot intended to receive said rod-shapedextension of said locking bolt head.